Vehicle Occupant Restraint Device

This application claims priority to Japanese Patent Application No. 2024-045749 filed on Mar. 21, 2024. The disclosure of the above-identified application, including the specification, drawings, and claims, is incorporated by reference herein in its entirety.

The present disclosure relates to a vehicle occupant restraint device.

An occupant protection device in which an airbag is assembled into a lap belt portion of a seat belt of a seat belt device with a vehicle seat is known. In the occupant protection device, when the seat belt is released, the seat belt cannot return to an initial position smoothly and quickly due to a weight of the airbag folded even in a case where the seat belt is intended to be returned to the initial position (retracted) by a spring force of a refractor. Therefore, the following measures have been proposed.

An interference suppression portion (recessed portion) that suppresses an interference with a shoulder belt portion during belt extension and belt retraction is formed solely in a region in the vicinity of a lower side of a belt extension port provided at a shoulder area of a seat back (refer to Japanese Unexamined Patent Application Publication No. 2023-132760 (JP 2023-132760 A)). A belt extension port provided at a shoulder area of a seat back is configured to have an opening direction to be rotatable from a forward direction, in which a seat belt can be extended forward, to an oblique direction, in which a tongue of the seat belt can be fastened to a buckle (refer to Japanese Unexamined Patent Application Publication No. 2023-160205 (JP 2023-160205 A)).

However, in a case where a mass of an airbag assembled to the seat belt is large, when the seat belt is released, simply suppressing the interference between the shoulder belt portion and the vicinity of the belt extension port or configuring the belt extension port to have a rotatable opening direction may not be sufficient to smoothly and quickly return the seat belt to an initial position due to a weight of the airbag. Additionally, there is a possibility that the released seat belt protrudes outward in a vehicle width direction and becomes caught in a side door when getting in and out of a vehicle. It is also conceivable to use a retractor with a motor, but a significant increase in cost is incurred.

The present disclosure provides a vehicle occupant restraint device capable of improving storability when a seat belt provided with a belt support airbag is released.

A first aspect of the present disclosure relates to a vehicle occupant restraint device including a seat belt, a belt support airbag, and a belt covering member. The seat belt is configured to restrain an occupant seated on a seat cushion of a vehicle seat to the vehicle seat. The belt support airbag is provided in a folded state in a lap belt or a shoulder belt of the seat belt and is configured to be inflated and deployed by gas supplied in an event of a frontal collision of a vehicle. The belt covering member is configured to cover at least a predetermined region of the lap belt on a belt anchor side and to urge the lap belt downward when the seat belt is released.

When the seat belt is released, at least the lap belt is stored to a side of the seat cushion due to a weight of the belt covering member. That is, the seat belt that is not retracted by a spring force of a retractor due to a weight of the folded belt support airbag is stored to the side of the seat cushion. As described above, storability when the seat belt provided with the belt support airbag is released is improved. The phrase “in an event of a frontal collision” of the vehicle mentioned here includes a time when a frontal collision of the vehicle is predicted (forecasted) to be unavoidable.

The belt covering member may be a resin plate having a substantially “C”-shaped cross section and extending along the seat belt.

Even with such a simple configuration, when the seat belt is released, at least the lap belt is smoothly stored to the side of the seat cushion due to the weight of the belt covering member.

The belt covering member may be easily bent inward in a vehicle width direction and may be difficult to be bent outward in the vehicle width direction.

When the seat belt is fastened, the belt covering member fits an abdomen of the occupant, and thus can suppress a decrease in waist restraint performance. Furthermore, when the seat belt is released, at least the lap belt is suppressed or prevented from protruding outward in the vehicle width direction and getting caught in a side door.

The belt covering member may be configured to urge the lap belt downward by a shaft portion spring member provided on a shaft portion of a belt anchor for the seat belt.

When the seat belt is released, since a spring force of the shaft portion spring member is applied to the weight of the belt covering member, at least the lap belt is quickly stored to the side of the seat cushion.

The belt covering member may include a lower half portion on the belt anchor side and an upper half portion on a side opposite to the belt anchor side. The lower half portion and the upper half portion may be rotatably connected by a support shaft.

When at least the lap belt is stored to the side of the seat cushion, the upper half portion can be rotated toward the lower half portion, and the seat belt in the stored state can be disposed closer to a side of the seat back. Therefore, the seat belt is less likely to become an obstacle when the occupant gets in and out of the vehicle seat.

The upper half portion may be urged to rotate toward the lower half portion by a support shaft spring member provided on the support shaft.

When at least the lap belt is stored to the side of the seat cushion, the upper half portion can be quickly rotated toward the lower half portion, and the seat belt in the stored state can be quickly disposed closer to the side of the seat back.

The vehicle seat may include a fixed armrest.

The occupant can get in and out of the vehicle seat solely from a seat front side. Therefore, even when the belt covering member does not have a configuration in which the belt covering member is divided into the lower half portion and the upper half portion, which are rotatably connected, the seat belt is less likely to become an obstacle when the occupant gets in and out of the vehicle seat.

As described above, according to the present disclosure, it is possible to improve storability when the seat belt provided with the belt support airbag is released.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. For convenience of description, regarding arrows appropriately shown in each of the drawings, an arrow UP indicates an upward direction of a vehicle and a vehicle seat, an arrow FR indicates a forward direction of the vehicle and the vehicle seat, and an arrow RH indicates a rightward direction of the vehicle and the vehicle seat. Therefore, in the following description, in a case where up-down, front-rear, and right-left directions are described without particular mention, up-down, front-rear, and right-left directions in the vehicle and the vehicle seat are represented. In addition, the right-left direction is the same as a vehicle width direction and a seat width direction.

As shown in, a vehicle occupant restraint deviceaccording to the present embodiment is provided on a vehicle seat. The vehicle seatis a front seat or a rear seat of a vehicle (automobile), and includes a seat cushion, a seat backthat is provided to be rotatable about a seat width direction as an axial direction at a rear end portion of the seat cushion, and a headrestthat is provided to be movable up and down at an upper end portion of the seat back. As shown in, there are cases where the vehicle seatis provided with a fixed armrest.

Inand the like, a collision test dummy (human body dummy) is shown seated on the seat cushionof the vehicle seatas a model of an occupant (seated person) to be protected. The dummy is, for example, an AM50 (50th percentile of US adult male) dummy (Hybrid III) for frontal collision tests. The dummy is seated in a standard sitting posture determined by a collision test method. The vehicle seatis positioned at a reference set position corresponding to the sitting posture. The dummy is hereinafter referred to as an “occupant P”.

As shown in, the occupant P seated on the seat cushionof the vehicle seatis restrained to the vehicle seatby a seat belt (webbing)provided in a seat belt device. The seat belt deviceis a three-point seat belt device, and is a so-called seat-integrated seat belt device. In addition, in the following description, a part of the seat beltthat is stretched from a shoulder Ps to an abdomen Pt of the occupant P is referred to as a shoulder beltA. A part of the seat beltthat is stretched from right to left on the abdomen Pt of the occupant P is referred to as a lap beltB.

A bezelthat serves as an outlet of the seat beltis provided on an outer side in the vehicle width direction (first end portion side in the seat width direction) at an upper end surface of the seat back. A bucklefor securing a tongueprovided on the seat beltis provided on an inner side in the vehicle width direction (second end portion side in the seat width direction) of the seat cushion. As shown in, a retractorfor winding a first end portion side of the seat beltis attached to a lower portion of a side frame (not shown) provided on the outer side in the vehicle width direction inside the seat back.

As shown in, a second end portion of the seat beltis attached to a substantially rectangular flat plate-shaped belt anchor. Specifically, the second end portion of the seat beltis inserted into a slit portion (not shown) formed in a first end portion of the belt anchorand is folded back. The folded-back portion is sewn to the seat belt. A second end portion of the belt anchoris attached to a side frameprovided inside the seat cushionon the outer side in the vehicle width direction, so as to be rotatable around a shaft portionA with the seat width direction as an axial direction.

Additionally, the shaft portionA is provided with a torsion springB as a shaft portion spring member that urges a first end portion side of the belt anchorto rotate downward. As a result, when the seat beltis released, a belt covering member, which will be described later, urges the lap beltB downward by a spring force of the torsion springB in addition to a weight of the belt covering member. The spring force of the torsion springB is set to be weak enough to assist in rotation of the belt covering memberdue to the weight of the belt covering membersuch that the spring force does not become a resistance when the seat beltis fastened.

As shown in, a predetermined region of the lap beltB on a belt anchorside relative to a belt support airbag, which will be described later, is covered with the belt covering member. The belt covering memberis made of a resin plate that extends along the seat belt(lap beltB). As shown in, a flat plate-shaped inner platethat constitutes an inner part in the vehicle width direction is joined to a side wallA, which is an open side of an outer platethat has a substantially “U”-shaped cross section and constitutes an outer part in the vehicle width direction, by fitting, welding, or the like in a thickness direction to form a substantially “C”-shaped cross section.

That is, a slit portionA extending along an extension direction of the seat beltis formed in a center portion of the inner plate. The belt covering memberis attached to a predetermined region of the lap beltB by relatively inserting the lap beltB into the slit portionA. When the seat beltis released, the lap beltB is urged downward together with the belt covering memberby the weight of the belt covering memberand also by the spring force of the torsion springB provided on the shaft portionA.

As shown in, a seat side shieldmade of resin is provided in a side portion of the seat cushionon the outer side in the vehicle width direction. Then, a storage pocket portionA that can store the lap beltB and the belt covering memberthat are urged downward is formed at a lower portion of the seat side shieldon the outer side in the vehicle width direction.

Furthermore, the belt covering memberis configured to be easily bent inward in the vehicle width direction and to be difficult to be bent outward in the vehicle width direction. Specifically, the outer plateis formed of a soft resin material that is easily elastically deformed. The inner plateis formed of a hard resin material that is difficult to be elastically deformed. For example, the outer plateis made of a resin in which a rubber component is uniformly mixed with polypropylene (PP). The inner plateis made of a resin such as polypropylene (PP), polycarbonate (PC), or acrylonitrile butadiene styrene (ABS).

The belt covering membermay be configured to be easily bent inward in the vehicle width direction and difficult to be bent outward in the vehicle width direction by different shapes instead of different materials. For example, the belt covering membermay be configured to be easily bent inward in the vehicle width direction and to be difficult to be bent outward in the vehicle width direction by forming a plurality of cutout portions (not shown) at predetermined portions of the outer plateto be arranged at a predetermined interval in the extension direction of the seat belt. Different shapes enable easier and cheaper manufacturing than different materials.

As shown in, the belt covering memberincludes a lower half portionon the belt anchorside and an upper half portionon a side opposite to the belt anchorside. The lower half portionand the upper half portionare rotatably connected by a support shaft. Therefore, the inner plateis not provided in an end portionA of the lower half portionand an end portionA of the upper half portionthat are connected by the support shaft. The outer plateat each of the end portionsA,A does not have the side wallA (see) to which the inner plateis attached. That is, the outer plateat each of the end portionsA,A is simply formed in a flat plate shape.

Additionally, the support shaftis provided with a torsion springA (see) as a support shaft spring member. As a result, in the belt covering memberstored in the lower portion (the storage pocket portionA) of the seat side shieldon the outer side in the vehicle width direction, the upper half portionis urged to rotate from an upper side toward the lower half portion(in a clockwise direction in a side view shown in). The spring force of the torsion springA is also set to be weak enough to assist in manually rotating the upper half portionsuch that the spring force does not become a resistance when the seat beltis fastened.

As shown in, the vehicle seatis provided with an airbag device. The airbag deviceincludes an inflator (not shown) embedded in the seat cushionor the seat back, and the belt support airbagwhich is assembled to a surface side (a side opposite to an occupant P side) of a substantially center portion of the lap beltB in the seat width direction in a folded state in a normal situation. Therefore, the belt covering memberis provided on the belt anchorside relative to the belt support airbag.

The inflator is, for example, a gas-sealed (cold type) cylindrical inflator having a substantially cylindrical shape, and is attached to, for example, the side frameof the seat cushionon the outer side in the vehicle width direction or the side frame of the seat backon the outer side in the vehicle width direction. The inflator is connected in communication with the belt support airbagvia a flexible tube (not shown) or the like.

The inflator generates gas by being activated by a control device (not shown) provided in the vehicle when a frontal collision of the vehicle is detected or a frontal collision is predicted (forecasted) to be unavoidable (hereinafter referred to as “in an event of a frontal collision of the vehicle”) by a collision sensor (not shown) including a camera or the like.

That is, the control device is electrically connected to the inflator and the collision sensor, and is configured to activate the inflator based on information from the collision sensor in an event of a frontal collision of the vehicle. A form of the frontal collision of the vehicle in which the control device activates the inflator includes an offset frontal collision, such as an oblique collision or a small overlap collision, in addition to a full overlap frontal collision.

The gas generated from the inflator is supplied to an inside of the belt support airbag. As a result, the belt support airbaginflates and deploys forward to restrain and protect the occupant P, who tends to move forward due to an inertial force. The belt support airbagis formed in a bag shape by, for example, overlapping two sheets of base fabric and sewing peripheral edge portions of the two sheets together. Each sheet of base fabric is formed of, for example, a polyamide-based or polyester-based fabric material.

In the vehicle occupant restraint deviceaccording to the present embodiment having the configuration, an operation thereof will be described below.

As shown in, the belt support airbagthat inflates and deploys by being supplied with gas in an event of a frontal collision of the vehicle is provided on the surface side of the lap beltB in a folded state. Then, the belt covering memberthat covers the predetermined region of the lap beltB on the belt anchorside relative to the belt support airbagurges the lap beltB downward by the weight of the belt covering memberand also by the spring force of the torsion springB provided on the shaft portionA when the seat beltis released.

As a result, the lap beltB and the belt covering memberare stored in the lower portion of the seat side shieldon the outer side in the vehicle width direction, specifically, in the storage pocket portionA formed in the seat side shield. That is, the seat beltthat is not retracted by a spring force of the retractordue to a weight of the folded belt support airbagis stored to a side of the seat cushion.

As described above, according to the present embodiment, it is possible to improve storability when the seat beltprovided with the belt support airbagis released. As shown in, in some embodiments, the lap beltB and the belt covering memberare stored in the storage pocket portionA. Accordingly, the lap beltB and the belt covering memberare prevented from protruding outward in the vehicle width direction, and appearance of the vehicle seatis suppressed from being impaired.

The belt covering memberincludes the lower half portionon the belt anchorside and the upper half portionon the side opposite to the belt anchorside, which are rotatably connected by the support shaft. Therefore, in some embodiments, it is also desirable from the viewpoint of appearance, which will be described later, that the upper half portionis rotated toward the lower half portionwhen the belt covering memberis stored in the storage pocket portionA. As shown in, in the case of the vehicle seatin which the fixed armrestis provided on right and left side portions, the upper half portionmay not be rotated toward the lower half portion.

Specifically, in a case where the upper half portionis not rotated toward the lower half portionwhen the seat beltis released, as shown in, the shoulder beltA of the seat beltis stretched in a straight line between a front end portion of the seat side shieldand the bezel. That is, the shoulder beltA of the seat beltis disposed obliquely in a side view in front of the seat back.

Here, in a case where the fixed armrestis provided on the right and left side portions as in the vehicle seatshown in, the occupant P can get in and out of the vehicle seatsolely from a front side. Therefore, even in a case where the shoulder beltA of the seat beltis disposed obliquely in a side view in front of the seat back, the shoulder beltA is less likely to be an obstacle when the occupant P gets in and out of the vehicle seat. Therefore, in the case of the vehicle seatin which the fixed armrestis provided on the right and left side portions, the upper half portionmay not be rotated toward the lower half portion.

Furthermore, the belt covering memberis formed of a resin plate having a substantially “C”-shaped cross section and extending along the seat belt. Therefore, a significant cost increase is not incurred. Even with such a simple configuration, when the seat beltis released, the lap beltB and the belt covering membercan be smoothly and quickly stored in the storage pocket portionA by the weight of the belt covering memberand also by the spring force of the torsion springB provided on the shaft portionA.

Additionally, the belt covering memberis configured to be easily bent inward in the vehicle width direction and to be difficult to be bent outward in the vehicle width direction. Therefore, as shown in, when the seat beltis fastened, the belt covering memberfits the abdomen of the occupant P, and thus can suppress a decrease in waist restraint performance. Furthermore, when the seat beltis released, the lap beltB and the belt covering membercan be suppressed or prevented from protruding outward in the vehicle width direction, and the lap beltB and the belt covering membercan be suppressed or prevented from getting caught in a side dooror from not fitting into the storage pocket portionA.

Furthermore, as described above, the belt covering memberincludes the lower half portionon the belt anchorside and the upper half portionon the side opposite to the belt anchorside, which are rotatably connected by the support shaft. Therefore, as shown in, when the lap beltB and the belt covering memberare stored in the storage pocket portionA, the upper half portioncan be rotated toward the lower half portionsuch that the shoulder beltA in the seat beltin the stored state is disposed closer to a side of the seat back(rearward of the state shown in).